Layout the caps on top of the wall with the correct overhang front-to-back. See the gaps between each stone? You'll want to split the angle , so each cap gets cut at half the amount of the gap.For example, if you have a 45 degree angle, you would cut each cap at 22.5 degrees. If you were to cut just one end at 45 degrees, the depth of the cap would be different then the next adjoining piece. You should be able to use a straight edge and pencil, and just eyeball the correct angle- half of the gap between each cap. To get the best looking cuts, each cap (except the end caps) will be cut twice.